Circuit breaker



March 3, 1931. o. 5. JENNINGS CIRCUIT BREAKER Filed April 20. 1929 2Sheets-Sheet a a. n n 5 M A #M n. I F. l f-ull w 3 M x x a INVENTORO/fver .5. Jenn/hi5.

- ATTORNEY March 3, 1931 Q. 5. JENNINGS CIRCUIT BREAKER Filed April 20.1929 2 ShOQtS-Shb't 2 m m E V m -imxw aliker 6i Jenni/ya Patented Mar.3, 1931 v OLIVER S. JENNINGS, OF MANSFIELD, OHIO, ASSIGNOR TOWESTINGHOUSE ELECTRIC PATENT OFFICE & MANUFACTURING COMPANY, ACORPORATION OF PENNSYLVANIA CIRCUIT BREAKER Application filed April 20,

My invention relates to circuit breakers andparticularly to circuitbreakers for controlling small power and lighting circuits and which areparticularly adapted for use as entrance circuit breakers forhouse-wiring and as branch-line distributing-panel circuit breakers.

An object of my invention is to provide a circuit breaker of the typeillustrated in the eopending application filed August 11, 1927,

by Fred G. Von Horn, Serial No 212,289,

and assigned to the Westinghouse Electric & Manufacturing Company,wherein the structural details are of such design that the 5componentiparts of the circuit breaker may be inexpensively manufacturedand readily assembled.

A further object of my invention is to provide a circuit breaker of thetype abovementioned, that shall be of compact construction and adaptedfor mounting in the panel structure disclosed in my copendingapplication, Serial No. 356,647, and filed c0n currently herewith.

A further object of my invention is to provide a circuit breaker whereinthe component parts thereof may be mounted upon a single supportingplate to besecured to an insulating base, thereby reducing the number ofparts required and facilitating assembly 'of the device, as well asreducing the cost of manufacturing.

These and other objects that will be made apparent throughout thefurther description of my invention are attained by means of theapparatus hereinafter described and lllllS- trated in the accompanyingdrawings, wheremxi Figure 1 is an elevational view partially inlongitudinal section of a circuit breaker and enclosure embodyingfeatures of my inVention,

Fig. 2 is an elevational view partially in transverse section of thecircuit breaker shown in Fig. 1, the section being taken on the brokenline IIII thereof and further illustrating the manner in which aplurality of units are assembled when used in a panel structure,

Fig. 3 is a transverse section of a circuit 1929. Serial No. 356,646.

tively, ofthe operating lever and the cradle for supporting theswitch-operating toggle. Referring to the drawings, the circuit breakercomprises an insulating base 7 havmg a recess 8 therein, in whichthecircuit breaker unit is mounted. A supporting plate 9 is provided withthree integral base lugs 11. 12 and 13 that extend at right angles fromthe bottom edge of the supporting plate and serve as securing means forattaching the supporting plate to the base by meansof the screws 14;, asindicated in the drawings.

A. contact arm 15. comprising a'metal plate of U shape, is provided witha flexible extension 16 consisting of a copper strap 10 and a steelstrap 20. The contact 16 that carries the contact member 17 is adaptedto engage a; stationary contact plate 18 that is electrically connectedto afeed bus 19 disposed in the recess 21 in the base 7 T he side plates22 of the contact arm 15 are pivotally mounted upon a rigid shaft 23that is securely riveted at 24 to the supporting plate 9, the sideplates being insulated from the shaft 23 by means of an insulatingbushing 25 that surrounds the shaft and upon which the contact armturns.

The contact arm 15 is insulated. from the supporting plate 9 by aninsulating washer 26 and from the enlarged retaining head 27 of theshaft 23 by the insulating washer 28. It will be seen from the foregoingthat the switch arm is entirely insulated from the supporting structureand may be moved to the full-open position shown in Fig. 4:.

The contact arm is actuated by means of a toggle 29 which comprises apair of links '31 and 32, the former being pivotally connected to thecontact arm 15 by means of a shaft 33, it being understoodthat the link31 is completely insulated from the contact arm by means of insulatingbushings 34. 35 and spacing bushings 36 (see Fig. 2). The link 31consists of two pieces of sheet metal that are held together by rivet37, the upper ends being separated, as indicated in Fig. 3, to straddlethe lower end of the-link 32. The knee-pivot shaft 38 of the toggleextends through both links and is notched at its ends for receiving thelooped ends of a pair of operating springs 39, the purpose of which willmore fully appear. The central portion of the shaft is enlarged at 40 tocenter the shaft and prevent longitudinal development thereof.

The upper end of the toggle link 32 is piv otally supported in a notch41 of V-sliape in an arm 42 of a cradle 43 that comprises a sheet-metalplate bent in U-shape to constitute the cradle 43 having an integralstop arm 44. The cradle 43 is pivotally mounted upon the supportingplate 9 by means of a shaft 45 that is rivetedto the supporting plate 9.

The cradle 43 is retained in the closed position shown in Fig. 1 bymeans of a bimetal thermal element 46 having a latch 47 that isinsulated from the element by means of insulating washers 48, the latchserving to en gage a shoulder 49 on the cradle arm 42 and releasablyretain it against clockwise rota- 1 tion to the open position of thecradle shown in Fig. 4. a

An operating lever 51 is pivotally mounted upon the supporting plate 9on the side op posite that upon which the contact arm is mounted, bymeans of a shaft 52'that is riveted to the supporting plate. The lever51 is provided with a reinforcing flange 53 (Fig. 5) for sti-fiening thesheet-metal lever tends-through the hole 57, as indicated in left,causest make the toggle and close'the contact arm,

' Figs, 3 and 4. T he springs 39, therefore, normally exert tension upontheknee pivot of the toggle, tending to collapse or break the toggle andcause the contact arm to move to open position, When the cradle 43 is inthe closed position shown in Fig. 1, movement of the operating handle tothe right or to the e toggle links to straighten or or break and openthe contact arm, respectively.

The springs 39 are commonly known as over-center springs which serve toeither make or break the toggle with a snap action after the operatinglever has moved a predetermined distance. When the carriage is released,by reason of the thermal element mov- In order to reset the cradle tothe clo scd position shown in Fig. 1, the operating lever 51 V isprovided with an arm 59 having an angularly disposed finger- 61 thatengages the end of the cradle arm 44, andmoves the cradle 43'from theopen position shown in Fig. 4 to the set position shown in Fig. 1 whenthe lever 51 is moved to the left or in a counterclockwise direction.The finger 61 moves the cradle arm 44, and the cradle arm 42 snapsbeneath the latch 47 which is momentarily displaced by the curved edge62 of the arm 42. The opening movement of the cradle 43 is limited by afixed stop arm integral with the supporting plate 9. This stop arm alsolimits the opening movement of the switch contact 17, as indicated inFig 4.

The operating lever 51 is provided with .an

insulating operating handle 63 that is at-,

tached to the lever 51 by means of a screw 64. The handle is providedwith extensions 65 that serve to close an opening 66 in the insulatingcover 67 that is mounted upon the insulating base 7 andattached theretoby any convenient means, such as that illustrated in my copendingapplication above referred to.

In order to facilitate extinguishing the are when the contact arm ismoved to open position, a plurality of metal arc-quenching barrierplates 68 are mounted in spaced relation and insulated from one anotherwithin the recess 8 of the base 7, as indicated in Fig. 1, the barrierplates being provided with slots 69 through which the contact 17 movesto open or to closed position. The action of the barrier plates is fulldescribed in my copending application, 'al No. 606,565 filed December13, 1922. The barrier plates, in this instance, are mounted u 11 aninsulating seat 71 that constitute anintegral part of the base 7, andthe lates are separated byan insulating washer 72, the plates and washerbeing retained in assembled position .by

means of a screw 73. Y

It be understood that the base and panel mounting herein shown isdisclosed in my copending application, Serial No. 356,647,

filed concurrently herewith, no claim being.

made to the circuit-breaker mounting in this -application.

- It will be understood that current enters the circuit breaker "throughthe feed bus 19 and passes, through the contact plate 18, contact 17.,flexible extension 16 and contact arm 15, to a flexible connector 7 4that is connected to one leg of the bimetalterminal element 46 which isof the usualU-shape. The other.

leg of the bimetal element is conductively connected to a terminalconductor 75 that ex tends exteriorly of the base and cover and isprovidedwith a terminal screw 76 to which the branch-line conductor maybe connected. It will be seen from the foregoing that, byreason ofmounting the component parts of tated. The number of parts is reducedand the cost thereof is also reduced to a minimum;

. The open construction of the circuit-breaker supporting. plate, acontact, arm pivo unit also renders the device-accessible for inspectionand repairs.

While I have illustrated but one embodi ment of my invention, it will beapparent to those skilled in the art that various changes,modifications, substitutions, additions and omissions may be made in theapparatus illustrated without departing from the spirit and scope of myinvention, as set forth in the appended claims. I glaim as my invention:I

v 1. A switch structure comprising a si 1e 3 mounted on one side of theplate, a cradle pivotally mounted on the same side of the plate, atoggle connecting the cradle andthe contact arm, an operating leverpivotally mounted on the other side of'the plate and having a portionoverhanging the edge of the plate and a spring connecting the togglepivotally connected to the overhangingportion of the o crating lever.

'Aswitci) f 111d d sup ortin p ate a air 0 para e ispose sha s fix'gi toone s ide of the plate and extending substantially normal to the plate,a switcharm having two spaced side plates pivotally mounted upon one ofthe said shafts, a to gle pivotally connected to the switch arm etweenthe side plates, a cradle of U-shape having two parallel spaced sideplates pivotally mounted upon the other shaft and having a pivotalconnection to the said toggle, anoperating lever pivotally mounted onthe other side of the supporting plate and having a portion overhangingthe edge of the supporting plate, releasable means for supporting thecradle inoperative position wherein the toggle mayretain the contact armin closed position and a pair of springs pivotally connected to the kneepivot of the toggle on opposite sides of the toggle structure comprisinga single and to the said overhanging portion of the 1 lever foractuating the toggle and'contact arm when the latter has moved apredetermined distance.

i In testimony whereof, I have hereunto subscribed my name this 3 da ofApril 1929.

OLIVER JENNINGS.

and said portion for actuating the tog le when the operating lever hasmoved a pre epivotally mounted on the same side ofthe plate, a toggleconnecting the cradle and the contact arm, an operating lever pivotallmounted on the other side of the plate an having a portion overhangingthe edge of .the plate, a spring connecting thetoggle and said portionfor actuating the toggle andthe contact arm, when the operatinglever-"has moved a predetermined distance and currentresponsive meansforv releasably retaining the cradle in operative position in which thetoggle may releasably retain the contact arm in closed position.

3. A switch structure comprising a single supporting plate, a shaftfixed to one side of the plate and extending substantially'normal tothe'plate, a switch arm having two s aced side plates ivotally mountedupon t e shaft, a toggle pivotally connected to the switch'arm betweenthe side plates, an operating lever pivotally mounted on the other sideof the supporting plate an'd'having a portion overhanginfg plate and apair' 0 otall the edge-of the said 0' rating" rings P connected to t eknees-pivot of-the togg e on opposite sidesotthe'toggle-and isc

